package com.example.mybrowser;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class MD5CheckSum
{
	private static String toHexString(byte[] b) 
	{
		char HEX_DIGITS[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
		StringBuilder sb = new StringBuilder(b.length * 2);  
		for (int i = 0; i < b.length; i++) 
	    {
	    	sb.append(HEX_DIGITS[(b[i] & 0xf0) >>> 4]);  
	    	sb.append(HEX_DIGITS[b[i] & 0x0f]);  
	    }
	    return sb.toString();  
	}
	
	
	public static String getMD5byBytes(byte[] data, int offset, int size)
	{
		MessageDigest messageDigest = null;
		try
		{
			messageDigest = MessageDigest.getInstance("MD5");
			messageDigest.update(data, offset, size);
		
		}
		catch (NoSuchAlgorithmException e)
		{
			e.printStackTrace();
		}
		return toHexString(messageDigest.digest());
	}
}
